CHROMOSOMAL CHANGES ASSOCIATED WITH ALTERED BIOLOGICAL CHARACTERS IN HOMOLOGOUS TRANSPLANTS.
Final rept. no. 2, 28 Dec 65-27 Dec 66,
SASAKI FOUNDATION MEDICAL INSTITUTION TOKYO (JAPAN)
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Ascites tumor cells can sometimes undergo a marked chromosomal changes with altered biological characteristics during homologous transplantations. Comparative studies of such variant and original tumor cell lines were attempted, in order to demonstrate the nature of the changed transplants. In this studies, two variant cell lines of the Yoshida ascites sarcoma of the rat, which recently developed and designated as FY and PY-2, were employed. Each of them had a hyperdiploid or hypertetraploid chromosomal constitution differing from a hypodiploid set of the original Yoshida sarcoma cell. Marked differences between the variant and original cell lines were observed also in such aspects as ability to form cell-bonding in ascites, sensitivity to Nitrogen Mustard N-oxide, infiltrative or invasive growth, and also individual antigenicity. Characteristics of the variants were kept stable during 80 homologous transplantations in Donryu rats. The Donryu hosts inoculated with one of these variants survived longer than those with the original Yoshida sarcoma. It is of special interest that the variant showed a decreased malignant behaviors in the host, compared with the original tumor cells. Therefore, it may be said that tumor cells can mutate into a less malignant type of cells. However, a definite correlation between the change of chromosomes and the alteration of biological characteristics of the tumor cells which might be correlated to the changed chromosomes is still obscure. Author
- Medicine and Medical Research